Field of the Invention
The present invention relates to a shower apparatus that discharges aerated bubbly water.
Description of Related Art
A shower apparatus which discharges bubbly water by aerating water using a so-called ejector effect is known. Such shower apparatus can reduce the amount of water usage via aeration. Meanwhile, such shower apparatus also reduces a stimulus sensation felt by a user when discharged bubbly water hits skin of the user, and this has been presented a problem in that a comfort feeling of the user of the shower apparatus is impaired.
In view of the above, the applicant has proposed the shower apparatus described in JP2012-187346 A. The shower apparatus described in JP2012-187346 A periodically varies the amount of air mixed into the water, whereby pulsation is provided to bubbly water to be discharged. Such pulsation is felt by the user of such shower apparatus as a stimulus sensation. As a result, a stimulus sensation reduced by aerating water to be discharged can be supplemented by such pulsation.
Further, the shower apparatus described in JP2012-187346 A periodically changes the direction of a main water stream ejected toward an aeration unit from a throttle unit comprised inside the shower apparatus, by the effect of a swirl formed in the vicinity of such main water stream, whereby the above-mentioned pulsation is provided to bubbly water to be discharged. More specifically, the direction of ejection of water from the throttle unit, the shape of a channel wall surface, etc., are devised such that a state in which the direction of a main water stream has been changed due to a negative pressure produced inside a swirl and a state in which the direction of a main water stream has returned due to a swirl reduced in size (in turn, a reduced negative pressure) are repeated in a self-induced and periodic manner. In this way, only a simple configuration allows bubbly water to be provided with self-induced pulsation, without separately providing a complicated mechanism, such as a pump for periodically varying the pressure of the shower stream.
The shower apparatus described in JP2012-187346 A has a circular external shape when seen along a direction in which the bubbly water is discharged, and a throttle unit is disposed so as to radially eject water from the center part of such circular shape toward an outer circumferential part thereof. With such configuration, uniform (same phase and same period) pulsation is provided to the entire bubbly water to be discharged, leading to the stable continuation of such pulsation.
However, when a part for discharging bubbly water (water discharge unit) has an external shape different from a circular shape (a rectangular shape, oval shape, etc.), the phase and period of pulsation provided to bubbly water differ depending on the position of a nozzle hole, and this may cause unstable pulsation.
The possible reason for this problem is as set forth below. In a shower apparatus provided with a part for discharging bubbly water having, as its external shape, a shape different from a circular shape, the distance over which water ejected from a throttle unit reaches a part of the shower apparatus closer to an outer circumference thereof is not uniform in the entire shower apparatus, and such distance differs depending on the direction of ejection from the throttle unit. Further, the flow rate of the water that flows back through an internal space from the direction of the outer circumference toward the inner circumference, which is backflow water that contributes to the generation of a swirl in the vicinity of a main water stream, is not uniform throughout the inside of the shower apparatus. As a result, the size of a swirl that changes the direction of a main water stream, and the time when such swirl occurs, etc., will differ depending on the location, and the phase and period of pulsation provided to bubbly water are also not uniform in the entire shower apparatus (such phase and period will differ depending on the position of a nozzle hole). Pulsations with different phases may temporarily offset each other, and this causes unstable pulsation as a whole.